nicstarmac.copyright 2.7 KB

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  1. /* nicstar.c v0.22 Jawaid Bazyar (bazyar@hypermall.com)
  2. * nicstar.c, M. Welsh (matt.welsh@cl.cam.ac.uk)
  3. *
  4. * Hacked October, 1997 by Jawaid Bazyar, Interlink Advertising Services Inc.
  5. * http://www.hypermall.com/
  6. * 10/1/97 - commented out CFG_PHYIE bit - we don't care when the PHY
  7. * interrupts us (except possibly for removal/insertion of the cable?)
  8. * 10/4/97 - began heavy inline documentation of the code. Corrected typos
  9. * and spelling mistakes.
  10. * 10/5/97 - added code to handle PHY interrupts, disable PHY on
  11. * loss of link, and correctly re-enable PHY when link is
  12. * re-established. (put back CFG_PHYIE)
  13. *
  14. * Modified to work with the IDT7721 nicstar -- AAL5 (tested) only.
  15. *
  16. * R. D. Rechenmacher <ron@fnal.gov>, Aug. 6, 1997
  17. *
  18. * Linux driver for the IDT77201 NICStAR PCI ATM controller.
  19. * PHY component is expected to be 155 Mbps S/UNI-Lite or IDT 77155;
  20. * see init_nicstar() for PHY initialization to change this. This driver
  21. * expects the Linux ATM stack to support scatter-gather lists
  22. * (skb->atm.iovcnt != 0) for Rx skb's passed to vcc->push.
  23. *
  24. * Implementing minimal-copy of received data:
  25. * IDT always receives data into a small buffer, then large buffers
  26. * as needed. This means that data must always be copied to create
  27. * the linear buffer needed by most non-ATM protocol stacks (e.g. IP)
  28. * Fix is simple: make large buffers large enough to hold entire
  29. * SDU, and leave <small_buffer_data> bytes empty at the start. Then
  30. * copy small buffer contents to head of large buffer.
  31. * Trick is to avoid fragmenting Linux, due to need for a lot of large
  32. * buffers. This is done by 2 things:
  33. * 1) skb->destructor / skb->atm.recycle_buffer
  34. * combined, allow nicstar_free_rx_skb to be called to
  35. * recycle large data buffers
  36. * 2) skb_clone of received buffers
  37. * See nicstar_free_rx_skb and linearize_buffer for implementation
  38. * details.
  39. *
  40. *
  41. *
  42. * Copyright (c) 1996 University of Cambridge Computer Laboratory
  43. *
  44. * This program is free software; you can redistribute it and/or modify
  45. * it under the terms of the GNU General Public License as published by
  46. * the Free Software Foundation; either version 2 of the License, or
  47. * (at your option) any later version.
  48. *
  49. * This program is distributed in the hope that it will be useful,
  50. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  51. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  52. * GNU General Public License for more details.
  53. *
  54. * You should have received a copy of the GNU General Public License
  55. * along with this program; if not, write to the Free Software
  56. * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  57. *
  58. * M. Welsh, 6 July 1996
  59. *
  60. *
  61. */